Photocopy device having a translucent prism support



June 13, 1950 B. E. cu usER 2,511,102

PHOTOCOPY DEVICE mwmc A TRANSLUCENT PRISM SUPPORT Filed Aug. 26, 1947 JUL/ENTER. farm .5 C/uusea Patented June 13, 1950 PHOTOCOPY DEVICE HAVING AIRANSLU- CENT PRISM SUPPORT .Benn E. Clouser, Akron, Ohio, .assignor Etc {The B. F. Goodrich Company, New York, N. Y-,.2a corporation of New York Application August 26, 1947 Serial #No. *7705622 3 Claims.

Thisinventio'n relates to anapparatus for making photographic contact copies, and pertains more speciflcall-y to an apparatus for making simultaneous copiesof two adjacent pages of a ed sir-written pages.

the volume.

drawing Fig. 1.

or the like. having a high light-transmissivity such as opti- .2 cal iglass, high molecular weight transparent methyl methacrylate polymer, or other material which. exhibits the phenomenon of edge-lighting. The zprecise angle at which the two converging book magazine, or other bound volume ofrprint- .15 faces 14, meet is not .critica1,:but it will generally be found most convenient to have this one object of the invention is to providea simangle less than a right-angle,.particularly when ple and inexpensive device for making contact the apparatus is used to make copies of tightly Photocopies. Another objectis toprovide a-phobound volumes. Excellent results have been obtocopy device which islightinweight andreadily .10 tained using prisms in which the angle at the portable. Another object is :to .provide an appatopis an. angle between 10 and 50. ratusifor making a sharp and clear-cut contact The several faces of the prismllrmay be pro-. copy of, apa'ge in a bound volume, suchasa book vided with ;a, highly polished surface finish, if or magazine, without damage to the binding of desired,although it isgenerallypreferred to have Another object is to providean at .least the twoconverging faces l4 provided apparatus for simultaneously making clear-cut with a light-diffusing surface finish such as may contact "photocopies of two adjacent pages in .a be obtainedby etching, sand blasting, or the like. bound volume without damage to the binding. It has-been found that if all faces of the prism Other andfurther objects will become apparent havea polished finish, internal reflections from from the description which follows. '20 faces Hl 'aresuch that only the upper portion of The objects of this invention are attained by thelprism is uniformly lighted so that only that making use of a generally wedge-shaped lightportion oftheprism is usable. However, when conductive element which is inserted edge-first these converging faces I4 are provided with a between the pages of a book, for example, and light-'difiusingsurface finish, thereis nosubstanwhich serves to transmit light from a source op- 25 tial variation in the-intensity.v of illumination of posed to the base of the wedge to the pages which these faces from top to bottom. overlie the convergingfaces ofthe wedge. The end faces P5 of the wedge-shaped prism The invention may be best understood by refmember l2 preferably have either a specular surerence totheacco pa y g d w ng which-shows face or a-polished surface. It is usually desirable a-preferred-embodiment of my invention. In the so that these faces reflect light inwardly in order to avoid'insufficient illumination of small areas Fig. 1 is a view in perspective of one embodiin the upper corners of the wedge-shaped prism. ment of the invention showing a book and photo- Indeed, the end faces may be silvered or painted copy paper mounted for making copies; and in order to increase the proportion of light inter- Fig. 2 is a vertical section along line 2-2 of nally reflected, although this step is not necessary. For best results, it is usually desirable that As shown in the drawing, the apparatus inthe bottom of the prism have a highly polished cludes a light box II) which serves as a support surface finish. for a tubular incandescent bulb I l which may be It has been found that very satisfactory results connected to any suitable source of power (not 40 are obtained by machining the prism from a block shown). Light box In may be made of any suitof high molecular weight methyl methacrylate able material such as wood, sheet metal, or the polymer on a shaper without any additional like, and may be provided with a light-reflective polishing or finishing operations. In this case, it inner surface, if desired, although this feature is is preferred that the fine lines or grooves left not essential. The top of light box Ill is provided 5 upon the converging faces and bottom of the with an opening into which is fitted the base of prism by the shaper be parallel to the longitudia generally wedge-shaped light-conductive elenal axis or edges of the prism, and that the ment l2 resting at its ends on supporting memgrooves on the triangular end-faces be perpenbers l3, and having converging faces [4, generally dicular to the bottom face through which the triangular end-faces l5, and base [6. light enters. In this embodiment, it is found that The wedge-shaped element or generally trianfaces M are uniformly lighted throughout their gular prism 12 may be made of any suitable hard extent even though bottom face l6 does not have or rigid light-conductive material such as glass a smooth highly polished surface.

It is preferred to use a material In using the apparatus, a sheet of reflex photocopy paper I! is folded emulsion side out and inserted between the pages of the book l8 desired to be copied. The book and paper are then placed over the edge of the wedge-shaped prism as shown in Fig. 1, and the light is turned on for the length of time necessary to give the desired exposure. If desired, of course, the paper may first be placed upon the prism and the book placed over it. In some cases, it is desirable to place a sheet of light-weight cardboard behind each of the pages to be copied in order to ensure contact with the photocopy paper throughout the area to be copied. It has also been found advisable in some cases for the operator to press the book or other paper being copied against the prism, either manually or by means of suitable clamps or weights.

It will be noted that by means of this invention there is obtained close contact between the pages of the volume being copied and the photocopy paper over the whole area of each page up to its juncture with the adjacent page. As a result, the copies obtained by the use of this invention are free from the distorted or blurred areas commonly found near the inner margin of the page being copied when the copies are made by conventional methods. Furthermore, by means of this invention substantially uniform intensity of illumination is obtained throughout the extent of the page being copied so that there are no dark areas in the copy. It has been found that the precise location of the light source has little efiect upon the uniformity of illumination, although it is obviously desirable to use an elongated light source, as shown in the drawing, instead of a spot source. The distance between the light source and the base of the prism is subject to considerable variation. With a prism ten inches high, fifteen inches long, and two and one-half inches wide at its base, made of methyl methacrylate polymer, best results have been obtained by using an incandescent bulb from six to twelve inches long spaced about eight inches from the base of the prism. Satisfactory results have been obtained, however, even when the bulb is within one inch of the base of the prism, but care must be exercised to avoid overheating the prism in this case.

Although specific embodiments of my invention have been described herein, I do not intend to limit myself solely thereto, but to include all of the obvious variations and modifications falling within the spirit and scope of the appended claims.

I claim:

1. Photocopy device for making reflex photocopies by exposing photocopy paper in contact with the material to be copied, which device comprises a box having a lightreflecting inner surface and a generally rectangular opening in its top, a light source disposed within and supported by said box, and a solid prism of light-conductive high molecular weight methyl methacrylate polymer adapted to support said photocopy paper and material to be copied upon its convergent faces,

said prism being supported by said box with the base of said prism in said opening opposed to and spaced from the light source and the apex thereof extending upwardly from said box, the convergent faces of said prism having a light-diffusing uniformly roughened surface finish and having an included angle of 10 to 50 at the apex.

2. Photocopy device for making reflex photocopies by exposing photocopy paper in contact with the material to be copied, which device comprises a chamber having a light-reflecting inner surface and having an opening in its upper face, a light source disposed within said chamber, and a solid prism of light-conductive material adapted to support said photocopy paper and material to be copied upon its convergent faces, said prism being supported by said chamber with the base of said prism substantially filling said opening opposed to and spaced from the light source and the apex of said prism extending upwardly from said chamber, the convergent faces of said prism having a light-diffusing uniformly roughened surface finish and having an included angle of 10 to 50 at the apex.

3. The device of claim 2 in which said lightconductive material is a high molecular weight methyl methacrylate polymer.

BENN E. CLOUSER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,254,195 Beidler Jan. 22, 1918 1,351,562 Foster Aug. 31, 1920 2,227,850 Steinlauf Jan. 7, 1941 2,247,737 Weeks July 1, 1941 2,347,665 Christensen et al. May 2, 1944 

